https://bitbucket.org/zabb65/payday-2-modding-information/downloads/sound_conveter_v1.15.zip
There is an .exe inside,extract it on the folder where are your .stream files.Then you have to shift+right click on this folder and select Open command windows.Now,type in the cmd "wwise_ima_adpcm.exe -d_all" to decode all the .stream into wav.To do the opposite use -e_all.

Or just read this guide if you don't understand https://modworkshop.net/showthread.php?tid=770 (yeah it for music mods,but it's the exact process for every sound mod)